The present invention is directed in general to apparatus for the measurement of relative velocity between two relatively movable members and more particularly where such apparatus is of the type where metallic patterns on insulating substrates are inductively coupled and move with the members.
Transducers of the foregoing type have been used in both open and closed loop control systems to provide position information only. One type of such device is known under the trademark INDUCTOSYN which is manufactured by Farrand Controls, Inc.
Where the system to be controlled operates at a significant velocity a separate tachometer has been provided. This was especially necessary in a closed loop system where the feedback of velocity information is necessary to insure stability.
However, a tachometer is objectionable in adding extra cost to the system. It also has relatively low mechanical reliability because of the need of bearings, flexible couplings and brushes.